This invention relates to the art of dispensing wire and, more particularly to a wire payout for controlling the dispensing of large quantities of a continuous wire without tangling.
The present invention relates to feeding large quantities of a continuous wire from a container to a welding operation wherein the wire must be fed without tangling or interruption. Such containers are known in the art and are generally shown and described in Cooper U.S. Pat. No. 5,277,314; Cooper U.S. Pat. No. 5,819,934; Chung U.S. Pat. No. 5,746,380; Kawasaki U.S. Pat. No. 4,869,367 and Gelmetti U.S. Pat. No. 5,494,160. These patents are incorporated by reference herein as background information illustrating packaging and dispensing large quantities of wire. Further, these patents illustrate the importance of controlling the wire as it is being dispensed from the package to prevent tangling.
Seufer U.S. Pat. No. 5,816,466 illustrates the interaction between the wire package and the wire feeder which is a part of the welding apparatus and is incorporated by reference herein as background information.
The present invention is particularly applicable for use in connection with welding wire and, therefore, the invention will be described with particular reference to a payout or retainer ring used with a package containing a large quantity of welding wire stored therein as a coil containing many convolutions formed into layers. However, the invention has broader applications and may be used with any type of wire or other wire-like materials.
It is, of course, well known that welding is an effective method of joining metal components. Further, it is well known that utilizing a welding wire as a consumable electrode in the welding process enhances the weld. Accordingly, it is desirous to package welding wire so that it can be cost effectively utilized. Furthermore, welding applications wherein large quantities of welding wire are consumed necessitate welding wire packages which contain large quantities of a continuous welding wire. Accordingly, large welding wire packages have been created for these applications which allow for a significant amount of welding run time before the operation must be shut down to restring a new package of welding wire. This is particularly important for automated or semi-automated welding operations.
In order to work in connection with the wire feeder of the welder, the welding wire must be dispensed in a non-twisted, non-distorted and non-canted condition which produces a more uniform weld without human attention. It is well known that wire has a tendency to seek a predetermined natural condition which can adversely affect the welding process. Accordingly the wire must be sufficiently controlled by the interaction between the welding wire package and the wire feeder. To help in this respect, the manufacturers of welding wire produce a wire having natural cast wherein if a segment of the wire was laid on the floor, the natural shape of the wire would be essentially a straight line; however, in order to package large quantities of the wire, the wire is coiled into the package which can produce a significant amount of wire distortion and tangling as the wire is dispensed from the package. As a result, it is important to control the payout of the wire from the package in order to reduce twisting, tangling or canting of the welding wire. This condition is worsened with larger welding wire packages which are favored in automated or semi-automated welding.
The payout portion of the welding wire package helps control the outflow of the welding wire from the package without introducing additional distortions in the welding wire to ensure the desired continuous smooth flow of welding wire. Both tangling or breaking of the welding wire can cause significant down time while the damaged wire is removed and the wire is re-fed into the wire feeder. In this respect, when the welding wire is payed out of the welding wire package, it is important that the memory or natural cast of the wire be controlled so that the wire does not tangle. The welding wire package comprises a coil of wire having many layers of wire convolutions laid from the bottom to the top of the package. These convolutions include an inner diameter and an outer diameter wherein the inner diameter is substantially smaller than the width or outer diameter of the welding wire package. The memory or natural cast of the wire causes a constant force in the convolutions of wire which is directed outwardly such that the diameter of the convolutions is under the influence of force to widen. The walls of the welding wire package prevent such widening. However, when the welding wire pays out of the package, the walls of the package loose their influence on the wire and the wire is forced toward its natural cast. This causes the portion of the wire which is being withdrawn from the package to loosen and tend to spring back into the package thereby interfering and possibly becoming tangled with other convolutions of wire. In addition to the natural cast, the wire can have a certain amount of twist which causes the convolutions of welding wire in the coil to spring upwardly.
There are two aspects of controlling the unwinding of wire from a wire coil package. First is to prevent the upward springing of the wire convolutions within the wire coil package. The second is management of the wire as it travels from the wire coil package to the wire feeder so that it doesn""t spring back. Controlling the upward springing effect of the wire convolutions is achieved by maintaining the position of the wire convolutions at the top of the wire coil and especially at a point where the upward springing effect is at its greatest which is towards the radially outer portions of the package. With respect to controlling the wire as it travels between the payout and the wire feeder, it has been found that tensioning along with guiding the wire can reduce the twisting and tangling effects. In this respect, by creating a slight tension along with using a guiding mechanism, the wire is controlled as it moves between the wire coil package and the wire feeder and is prevented from springing back into the package.
Payout devices or retainer rings have been utilized to control the spring back and upward springing of the wire and to control the payout of the wire. This is accomplished by positioning the payout or retainer ring on the top of the coil and forcing it downwardly against the natural springing effect of the welding wire. The downward force is either the result of the weight of the retainer ring or a separate force producing member such as an elastic band connected between the retainer ring and the bottom of the package. Further, the optimal downward force during the shipment of the package is typically different than the optimal downward force for the payout of the welding wire. Accordingly, while elastic bands or other straps are utilized to maintain the position of the payout or retainer ring during shipping, the weight of the retainer ring is often used to maintain the position of the payout relative to the wire coil during the payout of the wire.
The outward flow of wire, or payout, is managed by the payout or retainer ring""s position on the top of the wire coil which holds the upper layers of the convolutions in place as the wire is withdrawn one convolution at a time. In addition, the payout or retainer ring includes an edge or surface, typically a radially inwardly facing edge or surface, which controls the payout of the wire. In this respect, the wire is pulled from the center of a ring shaped device and engages the radially inwardly facing portion thereof. The retainer ring further includes a mechanism to prevent the wire from springing around the radially outer side of the retainer ring. Prior art retainer rings utilize a unified ring structure which includes resilient members that tightly engage the inner surface of the outer package to protect the outer convolutions of the welding wire coil and prevent the wire from springing around the outside of the retainer ring.
In accordance with the present invention, provided is a payout for use in connection with a welding wire package which includes at least two separate and independent retaining rings of a light weight disposable material which cooperably control the payout of the welding wire. In this respect, a payout in accordance with the present invention includes at least one ring which rests on top of the coil of wire and which prevents the coil of wire from springing upwardly, and a second ring which at least partially rests on the one ring and which is spaced above the top of the coil of wire. The two rings, one of which may be a floating ring, cooperatively control the payout of the wire from the wire coil. By utilizing at least two rings, one of which may move independently of the other, simple ring structures can be used to optimize restraint of the wire from springing upwardly and to improve control of the payout of the wire from the wire coil.
A payout according to one aspect of the present invention can utilize both a radially inner and a radially outer stationary ring, which rings engage the top of the coil of wire and are radially spaced from one another to produce a circumferentially continuous wire payout gap therebetween which preferably is radially centrally of the inner and outer sides of the coil wire. In another embodiment, a floating ring is of the size and shape to partially cover the gap between the inner and outer rings. The wire, as it is payed out of the wire coil package, passes between one of the edges of the inner or outer rings and one of the edges of the floating ring which rotates about the coil axis and eccentrically relative thereto during payout. As a result, as stated above, simple payout or ring designs which are easy to manufacture can be used, and the individual rings can be designed for its specific purpose. This can include different material choices and different textures used along the guiding edges or other surfaces without requiring complex components or materials.
In accordance with another aspect of the invention the payout has only an outer stationary ring with a floating ring overlying the latter and surrounding the inner core of the welding wire package. In this embodiment, the wire is payed out between the inner edge of the outer ring and the inner core of the welding wire package and the inner edge of the floating ring controls the payout of the wire. In yet another embodiment, the gap between radially inner and outer rings is covered by the bristles of a brush ring secured to one or the other of the inner and outer rings, whereby payout of the wire is controlled by the resistance of the bristles.
The primary object of the present invention is the provision of a payout for a wire coil package which allows the continuous and uninterrupted withdrawal of a welding wire from the package smoothly and without tangling.
Another object is the provision of a payout of the foregoing character that utilizes non-intricate components which complement one another to achieve the desired continuous and uninterrupted withdrawal of the welding wire.
Still another object is the provision of a payout of the foregoing character which is light weight and disposable.
A further object is the provision of a payout of the foregoing character wherein the wire is withdrawn from the package along a circumferential path which is radially central with respect to the coil of wire.
Yet a further object is the provision of a payout of the foregoing character that utilizes at least one ring which rests on the top of the wire coil and a floating ring which rests on the top of the one ring wherein the one ring and either a second ring or a core component are spaced from one another forming a continuous gap therebetween and the floating ring partially covers the gap progressively about the axis of the coil during payout with the welding wire passing through the gap.
Another object is the provision of a welding wire package of the foregoing character which utilizes components that are economical to manufacture, easy to use in the field and which are economically disposable.